Banning deception in economic experiments does not exclude experiments with participants in the role of experimenters who can gain by deceiving those in the role of participants. We compare treatments with and without possible deception by experimenter-participants to test whether deception aects behaviour of participant-participants in a dictator experiment and whether participants in the role of experimenters engage in deception. We nd no dierence in behaviour of participant-participants between the treatments whereas most participants in the role of experimenters engage in deception.